h: 


I 


ii 2 


A Practical  Test  of  the  Copper 
Sulphate  Method  for  the  Removal 
of  Micro-Organisms  From  Water 


Reprinted  from  Annual  Report  of  American  Public  Health  Association 


By  F.  S.  Hollis,  Ph.  D.,  New  Haven,  Conn 


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UNIVERSITY  OF  ILLINOIS 
LIBRARY 

Class  Book  Volume 


Je  07-2M 


REMOTE  STORAGE 


'‘-^VVVN.  ( 


A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD 
FOR  THE  REMOVAL  OF  MICRO-ORGANISMS 
FROM  WATER. 


By  F.  S.  HOLLIS,  Ph.  D.,  New  Haven,  Con,n, 

0 1 ' w 


In  Bulletin  No.  64,  Bureau  of  Plant  Industry,  U.  S.  Departmen/t  pf( 
Agriculture,  Dr.  George  T.  Moore  and  Mr.  Karl  F.  Kellerman  pub- 
lished in  May,  1904,  a method  for  destroying  or  preventing  the  growth 
of  algae  and  certain  pathogenic  bacteria  in  water  supplies  by  the  use 
of  copper  sulphate.  The  method  was  based  on  a thorough  review  of 
the  subject  of  the  toxicology  of  copper,  extended  laboratory  experi- 
ments under  different  conditions  upon  the  action  of  copper  sulphate  on 
various  micro-organisms,  certain  bacteria  and  such  higher  forms  as 
fish  that  might  be  influenced  by  its  presence.  In  addition  they  gave  the 
results  of  several  practical  applications  in  reservoirs  of  moderate  size 
and  a considerable  experience  in  its  application  to  the  water  of  cress 
beds. 

During  the  past  summer  numerous  practical  applications  of  the 
method  have  been  made  either  by  Dr.  Moore  and  Mr.  Kellerman  or 
with  their  advice,  as  well  as  by  independent  workers,  the  results  of 
most  of  which  are  as  yet  unavailable. 

The  method  is  one  which  has  caused  general  interest  as,  heretofore, 
all  that  could  be  hoped  for,  even  with  a regular  and  systematic  micro- 
'scopical  examination  of  the  water,  was  to  be  able  to  avoid  as  far  as  pos- 
sible growths  of  micro-organisms  by  drawing  the  water  from  such  part 
of  the  reservoir  or  from  such  depth  as  was  found  to  be  least  infected 
with  growths.  This  was  possible,  as  a rule,  only  in  the  larger  reser- 
voirs so  constructed  that  water  could  be  drawn  from  different  depths 
and  in  cases  where  the  growth  had  a somewhat  localized  vertical  dis- 
tribution. Little  help  was  offered  in  the  more  numerous  shallow  res- 
^ ervoirs  in  which  growths  are  most  likely  to  develop  in  greatest  abund- 
ance, unless  the  system  consisted  of  several  reservoirs  and  the  infected 
reservoir  could  be  temporarily  cut  out  of  the  supply. 

The  following  account  is  of  a practical  test  of  the  method  on  the 
two  storage  reservoirs  of  the  Greenwich,  Conn.,  Water  Company,  made 
with  the  advice  of  Dr.  Moore  and  Mr.  Kellerman,  and  is  offered  in  the 
hope  of  enlisting  interest  in  the  trial  of  a method  which  seems  to  prom- 
ise  much  and  as  a record  of  one  of  the  many  results  that  must  be  col- 
lected before  comparisons  can  be  made  which  will  lead  to  a complete. 


2 A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD . 


understanding  of  the  possibilities  and  limitations  of  the  method  and  the 
best  method  of  applying  it. 

The  reservoirs  are  situated  at  about  the  center  of  the  township  of 
Greenwich,  four  and  five  miles  north  of  the  most  populous  part  and  are 
used  also  as  a source  of  supply  for  Port  Chester  and  part  of  Rye.  They 
are  fed  with  surface  water  and  to  some  extent  from  springs,  have  but 
small  and  short  influent  streams  and  are  situated  in  adjoining  drainage 
areas.  Most  of  the  land  for  some  distance  back  from  the  shore  is 
owned  or  controlled  by  the  water  company. 

ROCKWOOD  RESERVOIR. 

The  upper  or  Rockwood  reservoir  has  an  area  of  93  acres  with  about 
7 of  shallow  flowage,  an  average  depth  of  20  feet  and  a capacity,  when 
filled  to  the  overflow  at  an  elevation  of  323  feet,  of  325,000,000  gallons. 
The  drainage  area  contains  about  one  square  mile  and  is  hilly  and 
partly  under  cultivation.  About  the  upper  tenth  is  cut  off  from  the 
main  body  by  a causeway  without  other  connection  than  through  the 
loose  stone  work  and  filling.  The  reservoir  was  formed  in  1893  by 
building  two  dams  or  dykes  and  without  removing  surface  soil  from  the 
meadow  land  and  pasture  which  was  flooded.  Trees  that  were  within 
the  area  of  the  reservoir  were  cut  near  the  ground  and  the  stumps 
mainly  left,  some  of  which  are  exposed  at  low  water. 

PUTNAM  RESERVOIR. 

The  lower  or  Putnam  reservoir  has  an  area  of  about  100  acres  with 
four  or  more  of  shallow  flowage,  an  average  depth  of  15,  to  20  feet  an^ 
a capacity  when  filled  to  the  overflow  at  an  elevation  of  290 . 5 feet  of 
300,000,000  gallons.  The  drainage  area  contains  about  two  and  a half 
square  miles  and  a small  influent  stream  brings  considerable  water  at 
certain  seasons  from  the  upper  part  of  this  area,  which  is  hilly,  about 
one-third  wooded  and  the  remainder  partly  under  cultivation. 

This  is  the  older  of  the  two  reservoirs,  upon  which  work  was  com- 
menced in  1879  and  an  additional  storage  capacity  obtained  by  raising 
the  elevation  of  the  dam  in  1887.  No  surface  loam  was  removed. 

The  water  of  each  reservoir  has  given  more  or  less  trouble  in  the 
past  by  supporting  considerable  growths  of  floating  micro-organisms, 
and  every  spring  there  has  been,  especially  in  Rockwood  reservoir,  a 
large  development  of  the  larger  forms  of  Spiro gyra  and  Conferva. 

The  microscopical  examination  of  monthly  samples  from  Rockwood 
reservoir  for  1896  showed  a considerable  growth  of  Syne  dr  a between 
January  and  May  with  a maximum  growth  in  April,  of  Peridinium 
between  January  and  May  and  the  presence  of  a growth  of  Dinobryon 


A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD \ 3 


throughout  the  year  except  during  May  and  June,  with  very  large 
numbers  during  August  and  September.  t 

The  microscopical  examination  of  samples  from  Putnam  reservoir 
for  1898  showed  the  presence  of  a considerable  growth  of  Synedra  from 
January  to  August,  of  Anabcena  from  July  to  November,  with  the 
greatest  development  during  August,  of  Uroglena  from  August  to 
November,  reaching  highest  numbers  in  September  and  October  and 
of  Dinobryon  between  February  and  July,  with  particularly  high  num- 
bers during  May  and  June. 

Water  from  each  reservoir  flows  by  gravity  through  separate  pipes 
to  a filter-house  some  distance  below  Putnam  reservoir,  where  all  the 
water  is  treated  by  mechanical  filtration  before  it  enters  the  distribut- 
ing mains. 

The  filtration  plant  consists  of  four  vertical  tanks,  each  ten  feet  in 
diameter,  and  two  horizontal  tanks  each  ten  feet  in  diameter  and  twenty 
feet  long,  giving  a combined  capacity  of  two  million  gallons  or  more  per 
day. 

At  the  time  of  undertaking  the  experiments  about  3,000,000  gallons 
per  day  were  being  drawn  from  the  two  reservoirs,  about  half  of  which 
was  filtered  after  treatment  with  1.4  grains  of  alum  per  gallon,  and  the 
remainder  was  used  in  washing  the  filters,  which  was  done  thoroughly 
once  every  24  hours.  Later  the  amount  of  alum  was  reduced  somewhat, 
and  an  attempt  made  to  reduce  the  amount  of  water  used  in  washing  the 
filters. 

The  alkalinity  of  the  water  varied  between  13.8  and  15.6  parts  of  cal- 
cium carbonate  per  1,000,000,  and  was  more  than  was  necessary  to  react 
with  the  copper  sulphate  and  the  alum  in  the  subsequent  mechanicai 
filtration.  Copper  suphate  was  added  according  to  the  method  sug- 
gested by  Dr.  Moore,  by  suspending  it  from  the  boat  in  burlap  bags, 
oach  containing  25  pounds,  to  which  a fresh  charge  was  added  when 
the  first  lot  was  dissolved  to  from  5 to  8 pounds. 

. From  one  to  three  bags  were  used  at  a time  according  to  the  nature 
or  extent  of  the  growth  present  in  the  part  of  the  resevoir  under  treat- 
ment, as  determined  by  inspection  or  previous  microscopical  examina- 
tion. Most  attention  was  given  to  making  the  addition  along  the  shore 
and  in  the  bays  and  shallow  flowage  areas,  which  seemed  to  be  the 
important  breeding  places  of  growths.  Generally  a run  of  several 
hundred  feet  was  made  along  the  shore  to  some  fixed  point,  then  across 
■and  dqwn  the  opposite  shore  to  a fixed  point  and  again  across  to  the 
point  left  on  the  shore  first  treated,  thus  making  from  twelve  to  twenty 
trips  across  and  frequently  additional  trips  across  at  the  lower  or  wider 
part  of  the  reservoir  if  growths  were  abundant: 


4 A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD. 


The  time  required  for  making  the  application  was  two  and  a half 
hours  for  250  pounds  for  the  three  additions  of  this  amount  and 
three  hours  for  350  pounds,  or  about  fifty-five  minutes  for  each  hun- 
dred pounds. 

The  copper  sulphate  is  generally  spoken  of  as  being  precipitated  after 
being  dissolved  in  the  water,  but  it  is  a question  how  far  this  is  the 
case,  except  as  it  unites  with  the  organisms  and  is  precipitated  with 
them  after  their  death.  A mixture  of  copper  sulphate  with  water  hav- 
ing the  character  of  that  of  these  reservoirs  containing  as  much  as  1 
part  per  1,000,000  will  give  no  precipitate  on  standing  or  will  this 
amount  give  a precipitate  of  copper  in  any  of  the  forms  in  which  cop- 
per is  ordinarily  precipitated  in  testing  for  its  presence,  as  shown  by 
laboratory  tests  by  Dr.  H.  E.  Smith,  or  would  any  precipitate  be  ex- 
pected at  this  dilution  if  the  solubility  of  the  different  forms  of  copper 
is  considered.  This  makes  it  necessary  to  evaporate  a considerable 
amount  of  the  water  to  a very  small  volume  to  be  able  to  test  for  the 
presence  of  copper  in  the  water  after  treatment. 

It  must  be  borne  in  mind,  however,  that  as  originally  applied  from 
the  suspended  bags,  the  copper  sulphate  has  gone  into  solution  in  really 
a small  volume  and  this  concentrated  solution  is  readily  traceable  as  a 
colored  streak  as  the  boat  progresses.  This  is  usually  clear,  but  in 
certain  shallow  parts  of  the  reservoir  appeared  somewhat  turbid,  which 
may  have  meant  precipitation  or  merely  the  presence  of  a greater  quan- 
tity of  organisms  which  acted  to  reflect  the  light  against  the  blue  col- 
ored solution  as  a back  ground. 

Calculated  from  the  distance  along  the  shore  and  the  number  of  times 
that  the  reservoir  was  crossed,  and  using  the  average  cross  section  of 
the  number  of  bags  used,  it  appears  that  the  sulphate  actually  gave  a 
solution  in  the  line  of  the  boat  of  about  one  part  to  250  of  water  when 
adding  the  amount  calculated  to  make  one  part  in  5,000,000. 

From  this  line  of  strong  solution  mingling  takes  place  vertically  by 
settling  and  laterally  by  the  action  of  the  wind  and  the  forward  motion 
of  the  water  as  the  result  of  drawing  from  the  reservoir  at  the  dam. 
But  one  reservoir  was  treated  at  a time,  and  following  each  treatment 
the  reservoir  was  not  drawn  upon  for  two  days. 

Copper  sulphate  was  added  to  the  extent  of  one  part  to  250  as 
calculated  above  to  1.5  liters  of  unfiltered  and  filtered  water  collected 
on  December  19th,  from  Rockwood  reservoir  when  it  contained  organ- 
isms amounting  to  4389  standard  units  per  c.c,  mainly  of  Dinobryon 
and  Uroglena. 

In  each  case  a considerable  flocculent  precipitate,  colored  by  the 
copper,  was  formed,  which  settled  slowly  carrying  down  all  organisms 


A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD.  5 


in  the  unfiltered  sample  and  leaving  the  water  above  perfectly  clear. 
Enough  was  not  obtainable  to  furnish  material  for  a detailed  study 
as  to  the  nature  of  the  combination  formed  between  the  copper  and 
the  organisms. 

TREATMENT  OF  ROCKWOOD  RESERVOIR. 

On  first  visitifig  the  reservoir  on  July  nth,  it  was  found  to  have 
been  drawn  down  about  three  feet,  thus  reducing  its  contents  to 

235.000. 000  gallons.  The  spring  growth  of  Spiro gyra  and  Conferva , 
which  was  particularly  abundant  at  the  lower  end  of  the  reservoir 
had  become  discolored  and  had  either-  risen  or  was  rapidly  rising  to 
the  surface  and  being  distributed  by  the  action  of  the  wind.  This 
was  found  to  contain  little  more  than  the  sheath  of  the  Spiro  gyra  and 
Conferva , but  mixed  with  it  were  other  forms  especially  cyanophyceae 
among  which  were  large  amounts  of  Anabaena  flos  aqua  in  a develop- 
ing stage,  which  seemed  likely  to  become  the  next  growth  of  import- 
ance. Practically  all  of  these  patches  of  algae  growths  that  had 
risen  to  the  surface  were  collected  by  skimming  from  the  surface  or 
by  scraping  it  from  the  bottom  of  the  shallow  portions  which  had  been 
exposed  as  the  result  of  drawing  down  the  water. 

At  this  time  there  were  only  moderate  growths  of  floating  forms 
and  these  were  rather  more  abundant  at  the  upper  end  of  the  reser- 
voir and  near  the  dam.  Infusoria  constituted  a considerable  part 
of  the  growth  and  Chlamydomonas,  which  developed  so  as  to  be  the 
main  cause  of  trouble  throughout  the  remainder  of  the  summer,  was 
present  in  the  portion  of  the  reservoir  above  the  causeway  to  the 
extent  of  95  standard  units  per  cc.  Cyanophycese,  while  present  in 
the  patches  of  dead  algae  rising  to  the  surface  were  not  found  free 
in  the  water.  Another  set  of  samples  taken  on  July  26th  the  day 
of  making  the  first  application  of  one  part  of  copper  sulphate  to 

5.000. 000,  but  before  adding  it,  showed  that  during  the  interval  an 
increase  had  taken  place  throughout  the  reservoir,  the  average  of  total 
organisms  from  four  points  in  the  reservoir  being  452.  Anabaena  was 
not  present,  although  other  forms  of  the  cyanophycese  had  devel- 
oped to  a slight  extent.  Chlamydomonas  was  present  throughout  the 
reservoir,  but  not  in  large  numbers,  the  average  being  31.  Rotifera 
were  present  in  considerable  numbers,  the  average  being  122.  Bac- 
teria were  present  to  the  extent  of -from  58  to  204  per  cc.  in  different 
parts  of  the  reservoir,  being  most  abundant  at  the  upper  end  and  at  the 
dam,  the  average  for  the  four  points  of  collection  being  137. 

On  July  30th,  four  days  after  adding  the  copper  sulphate  to  the 
extent  of  one  part  to  5,000,000  the  average  of  the  total  organisms  had 


6 A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD. 


dropped  to  119,  showing  a decrease  of  about  74  per  cent;  Cvano- 
phyceae  were  absent  save  for  the  finding  of  a single  piece  of  Micro- 
cystis. Diatomacese  were  reduced  about  70  per  cent,  infusoria  85 
per  cent  and  the  Chlamydomonas  while  present  showed  a temporary 
reduction  of  80  per  cent.  Chlorophycese  showed  a reduction  of  only 
about  10  per  cent  and  from  20  to  30  standard  units  of  Sphaerozosma 
and  Protococcus  were  present. 

The  bacteria  were  increased  from  an  average  of  117  to  2737  or 
about  23.5  times  the  number  before  treatment.  The  numbers  from 
the  four  points  of  collection  varied  from  1800  to  4000. 

On  August  9th,  two  weeks  after  treatment,  a single  sample  was 
taken  near  the  dam  which  showed  that  the  bacteria  had  decreased  to 
420  as  compared  with  3,000  four  days  after  treatment  and  189  be- 
fore treatment.  Total  organisms  had  increased  to  194  from  91  and 
the  infusoria  to  63  from  16,  of  which  53  were  Chlamydomonas. 
As  the  difficulty  from  organisms  and  especially  from  Chlamydomonas 
continued,  another  application  of  one  part  to  5,000,000  of  copper  sul- 
phate was  made  on  August  23d,  making  the  total  amount  added  one 
part  to  2,500,000.  Before  making  this  application  another  set  of 
samples  was  taken  from  the  usual  four  stations,  which  showed  that 
the  average  of  the  total  organisms  had  increased  to  599.  Diatomacese 
had  increased  to  198,  chlorophycese  to  107.  Cyanophycese,  repre- 
sented by  Microcystis  alone  showed  an  average  of  28  and  infusoria 
1 15,  of  which  101  were  Chlamydomonas , which  were  less  abundant 
at  the  dam  than  elsewhere. 

On  August  26th,  three  days  after  the  application,  the  average  of 
total  organisms  from  two  of  the  stations  was  200,  a reduction  of  67 
per  cent,  of  infusoria  59,  of  which  45  were  Chlamydomonas , a reduc- 
tion of  49  per  cent.  Diatomacese  were  reduced  80  per  cent,  chlorophy- 
cese 50  per  cent  and  cyanophycese  were  absent.  A sample  taken  at 
the  dam  on  August  29th,  three  days  later,  showed  little  change. 

The  only  form  present  after  the  first  treatment  that  caused  trouble 
was  the  Chlamydomonas  and,  as  the  authors  of  the  method  had 
found  by  experiment  that  this  form  was  very  resistant  to  the  action 
of  copper  sulphate,  one  part  to  5,000  killing  but  few  after  the  pro- 
longed treatment  of  a week  and  as  the  account  of  the  treatment  of 
the  Elmira,  N.  Y.,  reservoir  with  one  and  one-third  parts  per  1,000,000 
seemed  to  show  that  this  amount  killed  certain  forms  of  fish  and 
pollywogs,  it  was  deemed  better  not  to  add  more  copper  sulphate 
which  we  felt  would  not  serve  to  kill  the  Chlamydomonas  unless 
added  in  quantities  greater  than  it  was  thought  best  to  add*.  Chlamy- 
domonas continued  to  give  considerable  trouble  during  the  early  au- 


A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD.  7 


tumn  imparting  its  peculiarly  sharp  and  unpleasant  odor  id  the  Water 
to  such  an  extent  that  it  was  not  entirely  removed  by  filtration,  but 
a sample  taken  early  in  November  showed  that  it  had  finally  disap- 
peared. 

A sample  taken  on  December  19th,  when  the  water  of  the  reservoir 
was  very  low  and  covered  with  ice,  showed  total  organisms  4389, 
of  which  4165  were  infusoria,  2812  being  Dinobyron  and  1287  Urog- 
lena.  As  Uroglena  is  believed  to  be  killed  promptly  by  the  presence  of 
one  part  of  copper  sulphate  to  2,500,000  and  experiments  have  shown 
that  it  is  practically  all  killed  after  sixteen  hours  by  the  presence 
of  one  part  to  5,000,000  or  even  one  part  to  10,000,000,  the  presence 
of  this  growth  speaks  against  much  of  the  copper  from  the  summer 
treatment  remaining  in  the  reservoir  in  an  active  form. 

I have  advised  adding  copper  sulphate  dissolved  from  bags  through 
holes  in  the  ice  along  the  long  narrow  line  of  the  reservoir,  trusting 
to  the  forward  movement  of  the  water  due  to  drawing  from  the 
lower  end  to  effect  mixing  with  the  water. 

'TREATMENT  OF  PUTNAM  RESERVOIR. 

On  first  visiting  the  reservoir  on  July  nth,  the  total  organisms 
were  found  to  vary  between  398  and  866,  the  average  of  four  samples 
from  different  points  being  691.  More  than  half  of  these  were  diato- 
macese,  mainly  Tabellaria.  Cyanophycese  were  present  throughout  the 
reservoir,  the  average  being  62,  with  Protococcus  the  most  abundant 
form.  Cyanophacese  were  absent  save  for  a little  Coelosphaerium  at 
the  upper  end  of  the  reservoir.  Infusoria  were  present  in  numbers 
varying  from  103  to  297,  the  average  being  167,  about  half  of  which 
were  P eridinium. 

Copper  sulphate  was  added  to  the  extent  of  one  part  to  5,000,000 
on  July  30th.  Before  making  the  addition,  samples  were  taken  from 
the  upper  part  of  the  reservoir  and  near  the  dam,  which  showed  that 
the  average  of  total  organisms  had  increased  to  1510.  The  diato- 
macese  had  increased  to  an  average  of  1202,  most  of  which  were  Ta- 
bellaria, chlorophyceae  had  decreased  to  32  and  infusoria  to  19,  the 
growth  of  Peridinium  having  largely  disappeared.  Cyanophycese  had 
increased  to  an  average  of  256,  the  growth  being  mainly  one  of  Ana- 
baena  gigantica  which  was  present  throughout  the  reservoir  and 
amounted  to  250  near  the  dam. 

The  water  weeds  which  were  abundant  especially  in  the  shallow 
bays  on  the  west  side  of  the  reservoir  were  thickly  covered  with  gela- 
tinous masses  having  a slight  green  color  under  the  hand  lens  and 
shown  by  the  microscope  to  be  composed  of  nostoc  or  masses  of  bluish 


8 A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD. 

green  filaments,  representing  a developing  stage.  The  bacteria 
were  loiv  the  average  being  but  87  per  c.  c.  On  August  9th,  ten 
days  after  the  treatment  the  total  organisms  had  decreased  to  an 
average  of  656  or  a reduction  of  56%  while  the  water  near  the 
dam  showed  a reduction  of  78%.  The  diatomacease  had  decreased 
to  an  average  of  206  or  a reduction  .of  83%.  Chlorophycese 
had  increased  from  32  to  232,  Protococcus  and  Dictiosphaerium  being 
most  abundant.  Infusoria  had  increased  from  an  average  of  19  to  199, 
Trachelomonas  being  most  abundant  and  amounting  to  283  at  the 
upper  part  of  the  reservoir.  Cyanophyceae  had  decreased  to  an  aver- 
age of  10  or  about  96%  and  the  growth  of  Anabaena  had  entirely  dis- 
appeared and  the  large  growth  of  nostoc  on  the  water  weeds  was 
nearly  gone.  Bacteria  had  increased  from  an  average  of  87  to  49  per 
cc.,  and  it  is  possible  that  during  the  interval  they  may  have  been  even 
higher. 

A set  taken  August  23rd  showed  an  increase  of  total  organisms  to 
an  average  of  1159,  due  mainly  to  an  increase  in  the  growth  of  Tabel- 
laria.  Cyanophyceae  were  entirely  absent  in  the  lower  part  of  the 
reservoir  and  were  represented  by  only  a small  amount  of  Microcystis 
in  the  upper  part.  Infusoria  had  decreased,  due  to  the  disappearance  of 
the  growth  of  Trachelomonas , but  Chlamydomonas  had  appeared  to 
the  extent  of  about  25  in  all  parts  of  the  reservoir. 

A second  application  of  copper  sulphate  of  one  part  to  5,000,000, 
making  in  all  one  part  to  2,500,000,  was  made  on  August  26th.  Before 
making  the  application,  a set  of  samples  was  taken  which  showed  an 
average  of  total  organisms  of  2159  or  about  double  the  number  present 
but  three  days  before,  due  to  a large  increase  in  the  growth  of 
Tabellqria.  The  chlorophyceae  showed  an  average  of  230,  infusoria 
an  average  of  37,  of  which  27  were  Chlamydomonas  and  cyanophyceae 
were  absent.  Bacteria  had  decreased  to  an  average  of  14 1 per  cc. 

On  August  29th,  three  days  after  the  treatment,  a sample  taken  at 
the  dam  showed  total  organisms  1117  or  a reduction  of  about  45  per 
cent,  chlorophyceae  showed  21 1 or  a reduction  of  only  8 per  cent,  cyan- 
ophyceae continued  absent  and  the  infusoria  showed  37  or  the  same 
number  as  before  the  second  treatment,  20  of  which  were  Chlamydo- 
monas. 

While  the  Chlamydomonas  was  not  removed  by  the  two  applications 
of  'copper  sulphate,  the  growth  did  not  assume  the  proportions  of  the 
one  in  Rockwood  reservoir  and  the  water  of  this  reservoir  remained 
such  that,  with  the  filtration,  there  has  been  little  if  any  cause  for  com- 
plaint. A sample  taken  on  December  19th  showed  but  a moderate 
growth,  the  total  amounting  to  246,  with  infusoria  66,  of  which  44 


A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD . 9 


were  Cryptomonas  and  no  Chlamydomonas.  The  few  chlorophycese 
amounted  to  43. 

The  rather  wide  variations  in  the  amount  of  amorphous  matter  in 
the  samples  is,  I believe,  to  be  accounted  for  wholly  by  the  action  of 
the  wind  which  caused  material  from  the  bottom  of  the  rather  shallow 
reservoirs  to  be  brought  up  and  mingled  throughout  the  water  of  the 
reservoir,  even  to  the  extent  of  causing  the  turbidity  as  determined 
by  disc  readings  to  vary  widely  on  different  days.  In  no  case  was  the 
nature  of  the  amorphous  matter  such  as  to  indicate  that  it  was  com- 
posed mainly  of  the  recently  killed  organisms  as  the  result  of  the 
sulphate  treatment. 

It  is  useless  to  attempt  to  draw  general  conclusions  from  such  com- 
paratively limited  data  from  experiments  on  only  two  reservoirs  con- 
taining water  of  similar  character,  as  it  is  by  no  means  certain  that 
similar  growths  in  water  of  a different  character  would  be  acted  upon 
in  the  same  way  by  similar  treatment. 

Certain  facts,  however,  are  so  marked  as  to  lead  to  the  belief  that 
they  represent  general  characteristics  and  may  be  expected  under  all 
conditions. 

The  most  marked  of  these  is  the  apparent  great  susceptibility  of  the 
cyanophyceae  even  to  small  quantities  as  shown  by  the  prompt  and 
complete  disappearance  of  the  considerable  growth  of  Anabaena  which 
was  uniformly  distributed  throughout  the  entire  water  of  Putnam 
reservoir  by  the  single  addition  of  copper  sulphate  to  the  extent  of 
one  part  to  5,000,000  and  the  rapid  disappearance  of  the  nostic  form 
from  the  water  weeds  by  the  same  addition,  a growth  which  I believe 
represented  a developing  stage  and  which  would  soon  have  been  scat- 
tered throughout  the  reservoir. 

As  growths  of  cyanophyceae  are  of  frequent  occurrence,  often 
reaching  large  numbers  and  nearly  always  impairing  the  character  of 
the  water  by  imparting  during  the  period  of  growth  as  well  as  of  decay 
a characteristic  odor  and  taste,  commonly  known  as  the  “pig-pen” 
odor,  the  method  would  seem  to  afford  an  easy  way  of  quickly  remov- 
ing objectionable  growths  of  this  kind  or  of  preventing  them  in  case 
regular  microscopical  examinations  are  made  which  forecast  their 
appearance. 

While  an  opportunity  was  not  offered  to  try  the  method  on  large 
growths  of  chlorophycese,  it  has  been  a matter  of  surprise  that  such  as 
were  present  were  apparently  but  little  influenced  and  in  a few  cases 
■developed  to  some,  extent  within  a few  days  of  the  time  of  the  treat- 
ment. 


10  A PRACTICAL  TEST  OF  THE  COPPER  SULPHATE  METHOD. 


Both  diatomacse  and  infusoria  appear  in  every  case  to  have  been 
reduced  temporarily  by  the  addition  of  such  amounts  as  were  used, 
thus  holding  them  temporarily  in  check.  The  amount  added  was,  how- 
ever, insufficient  to  more  than  retard  their  growth,  and  after  a short 
time  they  increased.  The  infusoria  appeared  to  be  less  active  imme- 
diately after  a treatment,  as  seen  in  the  microscopic  examination. 

It  is  even  a question  whether  certain  of  the  infusoria,  as  th  Chlamy- 
domonas  were  not  assisted  in  their  development  by  the  addition  of 
such  a quantity  of  sulphate  that,  while  it  did  not  materially  decrease 
their  numbers,  proved  fatal  to  other  forms,  thus  providing  them  with 
an  abundant  food  supply. 

The  temporary  increase  in  the  number  of  bacteria  may  readily  be 
accounted  for  in  the  same  way.  It  was  not  expected  that  they  would 
be  killed  by  the  amount  of  copper  sulphate  used,  which,  however,  was 
sufficient  to  kill  a great  many  of  the  micro  organisms,  thus  converting 
these  into  available  food  for  the  bacteria.  The  results  are  given  in 
a concise  form  on  the  two  following  tables. 


ROCKWOOD  RESERVOIR,  GREENWICH,  CONN.,  WATER  COMPANY. 

ORGANISMS  AND  AMORPHOUS  MATTER  EXPRESSED  IN  STANDARD  UNITS  PER  C.C. 

One  standard  unit  is  a square  field  20m  on  a side. 


JO  ‘dUIOX 

25. 5°  C 

25.5 

25.5 

25.5 

| 23.6 

| 23.6 

23.6 

| 23.7 

•o  '3  J3d  Buajoeg 

204 

58 

99 

189 

1 137  | 

'AlUIlBJllV 

15.2 

15.0 

14.0 

14.0 

14.6 

13.6 

13.8 

1 

14.0 

•snoi[daouxy 

| 405 

427 

417 

290 

1 

427 

506 

418 

433 

•Bjajtjoa 

1 

1 

75 

132 

0 

293 

LO  00  00  o o 

<N  rH  Tfi  00 

1 

ZZl  1 

•Bpodozixj^j 

1 

10 

0 

0 

15 

© o o o 

o 

Infusoria. 

■ 

Chlamydomonas 

95 

Chlamydomonas 

95 

Peridinium 

88 

1 

f Chlamydomonas  19  | 
\ 

[ Peridinium  62 

f Chlamydomonas  20 

[ Peridinium  88 

f Chlamydomonas  3 

\ 

{ Peridinium  75 

Chlamydomonas 

93 

1 

j 228 

159 

| 89 

119  | 

CO  <N  <N  O rH 

^ CO  t-  O 

t— 1 rH  rH  rH  (M 

o 

Cyanophyceae. 

WX 

: : 

Coelosphaeri’m 

13 

Microcystis 

25 

Microcystis 

25 

Microcystis 
' 25 

O O O o 

0 

25 

1 

| 25 

38  1 

1 ■ 

25  1 

00 

<N 

Chlorophyceae. 

| Conferva 

25 

Sphaerozosma 

63 

Staurastrum 

19 

1 

| Micrasterias 

68 

| Staurastrum 

12 

•l^ox 

rH  • CO  00 

<N  • (N 

00  Oi  00  C<1 

rH  00  00  ri  <M 

§ 

£>iatomaceae. 

i Navicula 

| 45 

Melosira 
| 50 

Melosira 
| 62 

Melosira 

53 

Melosira 

25 

Melosira 

63 

Melosira 

83 

Melosira 

38 

•pn°X 

1 

1 

45 

86 

98 

| 93 

105 

53 

87 

98 

I 

1 58 

•suisiubS-io  iejojl 

| 379 

| 390 

| 193 

| 542 

| 378 

| 458 

1 437 

| 531 

| 384 

<M 

in 

. S 

1 July  11 

“ 11 

“ 11 

“ 11 

July  26 

“ 26  1 

, ■ 1 

| “ 26 

1 

“ 26 

j 

Above  causeway  

Below  causeway  

I 

At  dam  j 

Above  causeway  

Below  calseway  

Middle  of  reservoir 

At  dam  

» 

0 

i 

► 

350  pounds  copper  sulphate  added  ( = 1 part  to  5,000,000)  on  July  26th  after  taking  above  samples. 


ROCKWOOD  RESERVOIR,  GREENWICH,  CONN.,  WATER  COMPANY— Concluded. 


U3JBM  JO  •dlUOJ, 

t 

25.0 

25.0 

24.5 

24.5 

24.5 

| 22.0 

| 22.0 

23.0 

23.5 

23.0 

23.0 

*o  o jod  Biaojosg 

1 

1800 

2150 

4000 

3000 

• 2737 

420 





257 

558 

00 

o 

1 

I 14.0 

14.0 

1 

14.0 

14.0 

© © o o © 

TJ4  ^ LO  LO  LO 

•snoqd.iouiy 

00  O 00 

CO  X-  X- 

T*  ^ CO  <M 

IO  X-  <N  o <N 

rH  GO  rH  1^  lO 

x-  io  »o  o 

CM 

O LO 

(N 

1750 

•Bjajpoji 

o 

O CO  o o 

8 

50 

as 

358 

1 

0 

110 

T*  O O 

CO  00  CO 

o 

© 

IO 

•Bpodoziqjj 

O O © o 

0 

0 

0 

0 

0 1 

°l 

o o o 

© 

© 

Infusoria. 

Chlamydomonas 

5 

f Chlamydomonas  9 

[Glenodinium  20 

f Chlamydomonas  4 

i Trachelomonas  8 

Chlamydomonas 

6 

Chlamydomonas 

53 

Chlamydomonas 

34 

Chlamydomonas 

226 

Chlamydomonas 

107 

Chlamydomonas 

35 

taking  -above  samples. 

Chlamydomonas 

35 

Chlamydomonas 

56 

Chlamydomonas 

43 

'lB4°X 

1 

32 

39  | 

12 

16 

lO  CO  X>*  Tft  w 

<M  CO  IO  CO  rH 

115  1 
after 

62 

56 

05 

io 

iO 

Cyanophyceae. 

1 , 

1 

1 . 

Microcystis 

10 

1 



Microcystis 

38 

Microcystis 

75 

1 



>00)  on  Aug.  9th 

ib;ox 

0 

0 

1 o | 

' , 

10  , 

0 

0 

54 

88 

0 

8 

28 

,000,0 

0 

f 

0 

© 

© 

Chlorophyceae. 

1 

Gloeocystis 

20 

Sphaerozosma 

28 

1 

Sphaerozosma 

25 

Protococcus 

23 

f Dictiosphaeri’m  45 

1 Sphaerozosma  40 
Dictiosphaerium 

38 

Gloeocystis 

25 

1 

ided  ( = 1 part  to  5 

| Sphaerozosma 

1 8 

1 Gloeocystis 

1 10 

'IBJOX 

^ co  o 

lO  00  Tti  LO 

_ 

59 

51 

203 

106 

| 

91 

| 29 

r-  io  oo 

CO 

© 

Diatomaceae. 

Melosira  | 
38 

Navicula 

13 

Navicula 

8 

Navicula 

10 

Melosira  1 
23 

Melosira 

88 

Navicula 

245 

Navicula 

168 

Navicula 

220 

copper  sulph; 

1 Navicula 
| 23 

| Navicula 

1 15  

Navicula 

88 

'lBl°X 

o co  »ra  io 

« rH  ^ ^ 

1 22 

l 

1 30 

i 

1 115 

| 248 

i 

! 183 

1 

i 245 

oo  ^ oo  x*» 

© rg  ^ CM 

x- 

CO 

8 

•suisxubSjo  Ib1°X 

1 16 

1 

1 Zl 

941 

681 

1 

! 

i 119 

194 

509 

1025 

| 402 

| 447 

| 599 

50  pou 

237 

163 

I 

IO 

<N 

<N 

o 

© 

o © © © 

CO  CO  CO  CO 

05  CO  CO  CO  CO 

<M  (M  oa 

bi 

< 

2i 

1 

| Aug.  26 

r 

1 “ 26 

Aug.  29 

Above  causeway  

Below  causeway  

Middle  of  reservoir 

At  darn’  

A 

At  dam  

Above  causeway  

Below  causeway  

Middle  of  reservoir 

At  dam  

• • 

. • 

• 

. 

. 

. 

• 

. 

>>  : 

j i,  • 2 : i 

0 > . b 

1 <u  . a 

« c f)  . i- 

) 3 . <! 

► CTJ  • K 

: l 6 < 

| -3 

13  -M 

CQ  < 

c : 

3 

) * 

: £ 

03 

-a 

< 

PUTNAM  RESERVOIR,  GREENWICH,  CONN.,  WATER  COMPANY. 

ORGANISMS  AND  AMORPHOUS  MATTER  EXPRESSED  IN  STANDARD  UNITS  PER  C.C. 

One  standard  unit  is  a square  field  20/*  on  a side. 


jo  -duiojL 


•d  -o  jad  Euajoeg 


•snoqdaouxy 


•Eaajpog 


•epodoziqg 


© <N  © 
00  lO  lO 


o o © o 


E E E 6 

.2  3 3 3 

.5  oo.  5 m.5  ic.S  < 

-T3  CO  T3  t"  -g  t-  -a  ' 


Ph  Ph  £ Ph 


cs  n) 
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WE2 

cs  rt 

a c 
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o <M 
o 
£ 


•IBIOX 


H H 


t •£ 

ja 

to  ns1-1 
H H 


smsxuBSao  IB?°X 


D £ 


E < 


a ^ 
a 

£ < 


250  pounds  copper  sulphate  added  ( = 1 part  to  5,000,000)  on  July  30th. 


Putnam  reservoir,  Greenwich,  conn.,  water  company— Concluded. 


jo  ’duiax 

24.5 

24.5 

23.0 

23.0 

24.0 

23.5 

•3  D J3d  BU343BJJ 

650 

333 

§ : : 

151  | 

131 

3 \ 

•iCjIUIlBJfiy 

14.8 

| 14.4 

15.6 

15.6 

•snoiidjouxy 

04  O 

CO  04 

ic  04 

757 

305 

15  § 

CO  IO 

lO 

04 

co 

o 

CO  o 

15 

50 

38 

^ O 

co  © 

C 

cr 

C 

o 

: co 

M?podoziiftj 

o o 

o o o 

o o o 

5 O 

Infusoria. 

Trachelomonas 

283 

| Trachelomonas 

20 

1 Chlamydomonas 

25 

Chlamydomonas 

24 

f Chlamydomonas  1 

[Trachelomonas  28 

Chlamydomonas 

26 

Aug.  26th. 

| f Chlamydomonas  20 

[Trachelomonas  15 

IB*°X 

iO  ^ 

00 

1 199 

78 

64 

r-H  O ^ 

t-  CO  ^ 

co  § co 

a; 

03 

V 

o 

>> 

a 

o 

G 

03 

u 

Oscillaria 

8 

Microcystis 

13 

| Microcystis 

1 25 

part  to  5,000,000 

1- 

iB*ox 

00  CO 

11 

25 

0 

% o O 

c 

> ||  o 

Chlorophyceae. 

Dictiosphaerium 

83 

Protococcus 

120 

Staurastrum 

56 

Staurastrum 

38 

| Staurastrum 

181 

1 

Staurastrum 

85 

ier  sulphate  added 

1 Staurastrum 

119 

lB*>X 

241 

223 

232 

105 

| 92 

05  rH  O 

05  iH 

CO  iH 

w 

<M 

> O'  rH 

i O rH 

1 U 04 

Diatomaceae. 

* 

- 

1 Tabellaria 

138 

Tabellaria 

155 

1 

Tabellaria  | 
831 

1 Tabellaria 

952 

Tabellaria 

1803 

Tabellaria 

1700 

250  pounds 

Tabellaria 

795 

•ib;ox 

00 

00 

S § s 

04  GO  rH 

| 923 

1 

1 

j 1916  | 
| 1812  | 

■'f  05 

g « 

•suisiubSjo  IbI°X' 

CO  LO 

00  ^ 

656  | 

1121 

1198 

1159 

2307 

! 

2011 

| 2159 

1117 

1 

s 

2 

05  05 

biD 

3 s 
< 

CO  CO 

<M  <N 

bo 

3 5 

< • 

1 

| Aug.  26 

| “ 26 

| 

1 

i Aug.  29 

Upper  part,  opp.  point... 

At  dam  

Average 

Upper  part,  opp.  point... 

At  dam  

Average 

Upper  part,  opp.  point... 

At  dam  

Average 

At  dam  

* 


